An orchidometer is a medical instrument used to measure the volume of the testicles and thus evaluate the physical development of boys going through puberty.
The orchidometer was introduced in 1966 by Professor Andreas Prader of the University of Zurich, and consists of a string of twelve numbered wooden beads of increasing size. Doctors sometimes informally refer to them as "Prader's balls", or "the medical worry beads". The beads are compared with the testicles of the patient, and the volume is read off the bead which matches most closely in size.
The orchidometer can be used to detect disease: underdeveloped testicles can be a symptom of testosterone deficiency. (See hypogonadism.)
Professor Stephen Shalet, a leading endocrinologist who works for the Christie Hospital in Manchester, is reported to have told The Observer, "Every endocrinologist should have an orchidometer. It's his stethoscope."
Further reading
External link
